How to Send a Letter or Postcard: Domestic

How to Send a Letter or Postcard: Domestic Sending a letter with USPS is easy! Instructions cover most letters and postcards sent domestically (inside the U.S.), including U.S. territories and military bases in the U.S. and abroad. Step 1: Choose Envelope or Postcard Envelopes are for sending flat, flexible items like letters, cards, checks, and forms. One First-Class Mail Forever stamp ($0.82) can send 1 oz (about 4 sheets of regular 8.5" x 11" paper) anywhere in the U.S. Envelopes must be rectangular and made of paper, with maximum dimensions of 11.5" long x 6.125" high. Content must be flat with no more than 1/4" thickness. Large envelopes (flats) start at $1.69 for postage. Nonmachinable envelopes (rigid, lumpy, with clasps/string/buttons, or square/vertical) cost $0.49 additional. Postcards cost $0.65 and are for short messages, standard-sized between 5-6" long and 3.5-4.25" high. Step 2: Address Your Mail Write return address (sender) in top left corner. Write delivery address (recipient) in bottom center. Print addresses clearly in capital letters using pen or permanent marker. Do not use commas or periods. Include ZIP+4 Code when possible. Return Address Format: - Full name or company name - Apartment or suite number - Full street address - City, State, ZIP+4 Code Delivery Address Format: - Recipient's full name or company name - Apartment or suite number - Full street address - City, State, ZIP+4 Code Puerto Rico Addresses: Include urbanization or community code (URB) on 4 lines. U.S. Virgin Islands: Use abbreviation "VI" Military/Diplomatic Mail (APO/FPO/DPO): Do not include city or country name for addresses in other countries. Include unit and box numbers if assigned. Step 3: Calculate Postage & Add Insurance or Extra Services First-Class Mail Forever stamp costs $0.82 for standard letters up to 1 oz. Postcard stamp costs $0.65. Additional postage for letters over 1 oz: $0.29 for each additional 1 oz up to 3.5 oz. Large envelopes up to 13 oz pricing varies per additional 1 oz. Nonmachinable items cost $0.49 additional. Buy postage at The Postal Store online, Post Office locations, self-service kiosks, or national retailers. Add-On Services: - Certified Mail: Proof of mailing and recipient signature - Registered Mail: USPS's most secure service with manual processing and secure handling - Return Receipt: Delivery record with recipient's signature - Adult Signature Required: Only adults 21+ can sign with valid ID Step 4: Send Your Mail Options include: raising mailbox flag, dropping in cluster mailbox outgoing slot, placing in blue collection box, or taking to Post Office lobby drop. For hand-cancellation postmark, request from Post Office retail counter associate (free). Important: Envelopes with postage stamps weighing more than 10 oz or thicker than 1/2" cannot go in collection boxes; must be given to Post Office employee. Bonus Tips: Stay flexible: Don't send rigid objects in paper envelopes. Flexible items like stickers and photos are acceptable if envelope remains flat and under 1/4" thick. Rigid objects (flash drives, coins, keys, hard plastic cases) should use padded envelopes or boxes as packages. For embellished invitations with wax seals/ribbons/strings, place inside another envelope or request hand-cancellation. Tracking available through Priority Mail Express, Priority Mail, Certified Mail, or Registered Mail services.